Mana.
It is a type of energy that all living things possess.
Of course, Axel himself, as a living being, innately possesses mana—an immense quantity at that. Though the Harem Settlement System is using 99% of his mana reserves to support its function, leaving him with only 1% to use for other purposes.
But his high innate mana is what put him in trouble at the moment.
The Mana Tonic, after all, increases one's base mana by a certain percentage if their mana passes a certain threshold, referencing the user's actual mana levels. And Axel's body couldn't really support 100% of his mana, much less increasing it by another 400%...
Thus, a mana overload happened.
The mana in his body, unable to find a way to "release" itself, was moving about chaotically, injuring his mana pathways, his blood vessels, organs, and everything else. If nothing was done, then his body would turn into mush, and he'd lose his life in a gruesome manner.
"Hey! Keep it together!"
But not all hope was lost.
